Don't throw "line too long" presubmit error on python import statements.

presubmit_canned_checks.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generic presubmit checks that can be reused by other presubmit checks."""
 
 import os as _os
 _HERE = _os.path.dirname(_os.path.abspath(__file__))
 
 # Justifications for each filter:
@@ skipping 327 matching lines @@
   # Language specific exceptions to max line length.
   # '.h' is considered an obj-c file extension, since OBJC_EXCEPTIONS are a
   # superset of CPP_EXCEPTIONS.
   CPP_FILE_EXTS = ('c', 'cc')
   CPP_EXCEPTIONS = ('#define', '#endif', '#if', '#include', '#pragma')
   JAVA_FILE_EXTS = ('java',)
   JAVA_EXCEPTIONS = ('import ', 'package ')
   OBJC_FILE_EXTS = ('h', 'm', 'mm')
   OBJC_EXCEPTIONS = ('#define', '#endif', '#if', '#import', '#include',
                      '#pragma')
+  PY_FILE_EXTS = ('py')
+  PY_EXCEPTIONS = ('import', 'from')
 
   LANGUAGE_EXCEPTIONS = [
     (CPP_FILE_EXTS, CPP_EXCEPTIONS),
     (JAVA_FILE_EXTS, JAVA_EXCEPTIONS),
     (OBJC_FILE_EXTS, OBJC_EXCEPTIONS),
+    (PY_FILE_EXTS, PY_EXCEPTIONS),
   ]
 
   def no_long_lines(file_extension, line):
     # Check for language specific exceptions.
     if any(file_extension in exts and line.startswith(exceptions)
            for exts, exceptions in LANGUAGE_EXCEPTIONS):
       return True
 
     file_maxlen = maxlens.get(file_extension, maxlens[''])
     # Stupidly long symbols that needs to be worked around if takes 66% of line.
@@ skipping 11 matching lines @@
 
     if line_len > extra_maxlen:
       return False
 
     if 'url(' in line and file_extension == 'css':
       return True
 
     if '<include' in line and file_extension in ('css', 'html', 'js'):
       return True
 
+    if 'pylint: disable=line-too-long' in line and file_extension == 'py':
+      return True
+
     return input_api.re.match(
         r'.*[A-Za-z][A-Za-z_0-9]{%d,}.*' % long_symbol, line)
 
   def format_error(filename, line_num, line):
     return '%s, line %s, %s chars' % (filename, line_num, len(line))
 
   errors = _FindNewViolationsOfRule(no_long_lines, input_api,
                                     source_file_filter,
                                     error_formatter=format_error)
   if errors:
@@ skipping 755 matching lines @@
   for f in affected_files:
     cmd = ['gn', 'format', '--dry-run', f.AbsoluteLocalPath()]
     rc = gn.main(cmd)
     if rc == 2:
       warnings.append(output_api.PresubmitPromptWarning(
           '%s requires formatting. Please run `gn format --in-place %s`.' % (
               f.AbsoluteLocalPath(), f.LocalPath())))
   # It's just a warning, so ignore other types of failures assuming they'll be
   # caught elsewhere.
   return warnings